The invention relates to structures which are self-adherent to the surface of the cornea and which are the vehicle of one or more medicaments for the eye.
In my U.S. Pat. No. 4,377,329, contact-lens configurations are described wherein the lens is a relatively small central component, and a surrounding haptic is a second component. The haptic is substantially fenestrated and is so thin and flexible that, although normally flat, being formed from flat sheet material, it is self-adapting to the curvature of the cornea, and it remains removably adhered to the cornea via normal moisture on the surface of the cornea. The entire structure is so thin as to cause no discomfort, in spite of normal eyelid action, and the eyelid action operates upon the fluid suspension of the haptic in such manner as to assure circulation of fluid in the moist region between all parts of the haptic and the cornea.
In a recent article entitled, "Polymers Release Drugs Continuously", High Technology, January 1983, pages 28 to 31, new drug systems are described for delivery of medical dosages at desired rates for extended periods of time. In particular, bio-compatible polymers are described wherein particular drugs are built into the polymer for diffusion, as from a capsule, in the course of time. Among the products described is a relatively expensive one for use in the eye, wherein a plastic disk sits continuously on the eyeball behind the lower eyelid, releasing pilocarpine for glaucoma therapy. The disk is said to function for a week, producing fewer side effects than the administration of pilocarpine with eyedrops. Such disks are relatively bulky and awkward to insert and remove, and they must be preshaped for conformance to the surface of the eyeball.